To me any contact with another human being in a sexual way other than your partner is a form of betrayal. Ask yourself this, if your other half was in the room and saw you doing something a little on the wild side, would he/she be uncomfortable with it? If yes, then it is wrong.
Besides when I am truly in love I only want to have sex with him and no one else but him. If he and I decide having threesome or whatever is something we would like to do then that is okay and it is something we share together. But anything sexual should be with each other or with each others approval. Just the way I am.
